The worse problem about letting go off bad habits is the impossibility to realize that you have a bad side.
If we are actually to be judges by ourselves. Everyone will always plead not guilty with every convinceable reasons so that is if you want to abstain from any character you must find every reasons to why you must do it.
It is addicted to you already so you must fight it out yourself at your realization of it.
Remember you are an adult that has grown beyond guidians or parental control that no one would force you to stay live a particular lifestyle. Then the courage from your self discipline and consciousness to disagree your bad habits to a good one will come.
Take your life seriously like no one can help you as much as you can help yourself by yourself then, You can always detect those bad habits as guilts and not good for you.